We recommend that you replace both springs on your door at the same time. We don't sell them individually for several reasons. When one spring breaks, the other is soon to follow. Spring sizes vary even within the same door weight based on the installer and the time period installed. Spring sizes have changed in the past few years as well, so we have no way to accurately match just one spring in a set. You have to replace both springs at the same time to make sure you get a balanced pair. Check out our Torquemaster spring how to's .